Apparatus for positioning a movable element



y 1957 K. c. GOODMAN 2,

APPARATUS FOR POSITIONING A MOVABLE ELEMENT Filed Dec. 6, 1955 2 she t -sheet 1 -INVENTOR. KENNETH C. GOODMAN AGENT July 2, 1957 K. c. GOODMAN 4 2,798,190

APPARATUS FOR POSITIONING A MOVABLE ELEMENT 2 Sheets-Sheet 2 Filed Dec. 6, 1955 INVENTOR. KENNETH c. GOODMAN AGENT Patented July 2, 1957 APPARATUS FOR POSITIONING A MOVABLE ELEMENT Kenneth C. Goodman, Columbus, Ohio, assignor, by mesne assignments, to American Brake Shoe Company, New York, N. Y., a corporation of Delaware Application December 6, 1955, Serial No. 551,361

4 Claims. (Cl. 318-31) This invention relates to apparatus for positioning a movable element, such, for example, as an antenna, from a position remote from the movable element.

One object of the invention is to provide an improved and simplified apparatus of the type set forth above.

Another object of the invention is to provide an improved and simplified apparatus of the type set forth above in which the movable element to be positioned is driven by a motor and which motor also drives a selsyn transmitter connected to operate a selsyn receiver positioned remotely from the movable element and at the position from which it is desired to position or control the position of the movable element, the apparatus including improved switch operating means operated by the selsyn receiver.

Another object of the invention is to provide improved and simplified apparatus of the type set forth above in which the movement of the movable element in either direction is limited and preferably, but not necessarily, an apparatus in which the direction of motion of the element being positioned corresponds with the direction in which the position determining element was moved.

Another object of the invention is to provide improved switch apparatus adapted for use, for example, an apparatus such as set forth in the foregoing objects.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the invention is clearly shown.

In the drawings:

Figure 1 is a diagrammatic view showing an apparatus embodying the features of the invention, the apparatus shown being employed for the purpose of positioning a radio antenna from a remote position;

Figure 2 is a view on a larger scale of a fragment of the selsyn receiver of the apparatus shown in Figure l and a switch which is operated thereby, which receiver and switch are positioned remotely from the antenna and at the position from which it is desired to control or determine the position of the antenna;

Figure 3 is a view in section, the section being taken on line 33 of Figure 2 looking in the direction of the arrows; and

Figure 4 is a view in section, the section being taken on line 4-4 of Figure 2 and showing mechanism for limiting the rotation of the switch adjusting means to 360 degrees.

The apparatus shown in the drawings was designed for the purpose of positioninga movable element from a remote position and it may be employed with advantage in controlling or operating substantially any movable element of substantially any apparatus. For the purpose of an example only, the apparatus is shown diagrammatically in Figure 1 of the drawings in connection with a movable element in the form of a rotatively adjustable radio antenna.

Referring to Figure 1 of the drawings, the apparatus includes a reversible electric motor 20, a self-synchronizing electric motor 21 mechanically connected to be operated by the motor 20 and a self-synchronizing electric motor 22 connected to be operated electrically by the self-synchronizing motor 21. It may be stated here that self-synchronizing motors such as the motors 21 and 22 and their operation are well known in the art and that the word selsyn, which is an abbreviation of the word self-synchronizing, is applied in the art to devices such as the motors 21 and 22 which are adapted to be connected electrically and in which, when so connected, an angular displacement of the rotating member or armature of one of the motors produces an equal angular displacement of the rotating member or armature of the second motor. For the foregoing reasons and to simplify this specification and the claims, the motor 21 will be referred to as a selsyn transmitter and the motor 22 will be referred to as a selsyn receiver.

The motor 20 is a low voltage reversible electric motor which preferably includes gearing between its armature shaft and its power output shaft whereby said output shaft will rotate at a slow speed and with a high torque, and as shown in the drawings an antenna mast 23 is mounted directly upon and is rotated by the power output shaft, not shown, of the motor 20. Also, as shown in the drawings, the selsyn transmitter 21 is positioned adjacent the motor 20 and its rotor or armature shaft 24 is driven by the motor 20 through the antenna mast 23 by an endless belt 25 and a pair of sheaves 26 and 27 on the armature shaft 24 and the mast 23, respectively. In the embodiment of the invention illustrated, the sheaves 26 and 27 are of equal diameter whereby the ratio of rotation of the armature shaft 24 and the antenna mast 23 is l to 1, but it will be seen that this ratio may be varied, if desired, to render the control apparatus more or less sensitive.

The selsyn transmitter 22 is placed at a position or station remote from the antenna and from which position or station it is desired to control the rotated positions of the antenna. The selsyn transmitter 21 and the selsyn receiver 22 are electrically connected in the usual manner through a plurality of wires 28, and, as previously set forth, when the apparatus is in operation the rotor or armature shaft 29 of the selsyn receiver 22 is synchronized to rotate with, and follow substantially exactly the degree of rotation of the armature shaft 2d of the selsyn transmitter 21. Selsyn receiver 22 operates a control switch 30, the function of which will be set forth fully hereinatfer.

Motor 20 is energized from the secondary winding 31 of a step-down transformer 32, the primary winding 33 of which is energized from a pair of conductors 34 and 35 which are connected to a volt source of alternating electric current through a main switch, not shown. Conductor 34 extends to one side of the primary winding 33 and conductor 35 may be connected either through the lower contacts of an electromagnetically operated switch 37, a lead 38 and a line 39 to the other side of the primary winding, or through a conductor 40, the lower contacts of an electromagnetically operated switch 41 and line 39 to said other side of the primary winding 33 depending upon which, if either, of the switches 37 or 41 is energized to its closed position.

The secondary winding 31 of transformer 32 may be connected to the motor 20 to cause the latter to operate in reverse directions and to stop through a lead 42 connected to one side 'of the winding 31 and one of the upper contacts of each of the switches 37 and 41. The other upper contact of switch 41 is connected to motor 2% through a lead 43 and the other upper contact of switch 37 is connected to motor 20 through a lead 44. A line 36 connects the other side of winding 31 to the motor 20. Switches 37 and 41 are normally open and, of course, when they are open the transformer 32 is not energized. If switch 41 is energized, it will move to the position shown in Figure l of the drawings and bridge its lower contacts t'ofiritercon nect electrically the conductor 40 and the line 39 to energize the primary winding 33 of transformer 32 Upon closing, the switch 41 will also bridge its upper contacts to interconnect electrically the leads 42 and 43 to place the motor 20 in a circuit with the secondary winding 31 of transformer 32 whereby the motor 2 will be energized to rotate in one direction. Switches 37 and 41 are never energized simultaneously and when switch 41 is open and switch 37 is energized it will close to interconnect electrically the conductor 35 and line 39 to energize the primary winding 33 of transformer 32. Upon closing switch 37 will also bridge its upper contacts to interconnect electrically the leads 42 and 44 to place the motor 20 in circuit with the secondary winding 31 whereby the motor 20 will be energized to rotate in a direction opposite to that in which it rotates when switch 41 is energized as described above. The selsyn motors 21 and 22 are energized through lines 45 and 46 which are connected, respectively, with conductors 34 and 35.

Switches 37 and 41 are energized from a second stepdoWn transformer 47 the primary Winding of which is connected to the conductors 34 and 35. One side of the secondary winding 48 of transformer 47 is connected through a lead 49 to one end of each of the coils 50 and 51 of the switches 37 and 41, respectively. The other end of coil 50 is connected through a lead 52 to the upper contact arm 53 of switch 30 associated with the selsyn receiver 22 and the other end of coil 51 is connected through a lead 54 with the lower contact arm 55 of switch 30 (see Figure 2). The center contact arm 56 of switch 30 is connected to the other end of the secondary winding 48 by a lead 57.

Switch 30 is generally of conventional construction and it includes the three contact arms 53, 56 and 55 which are electrically insulated from each other and are mounted adjacent one end upon an arm 58. The contact arms 53, 56 and 55 of switch 30 are leaf springs and the electrical contacts thereon normally do not contact each other so that the switch 30 is a normally open switch. When the center contact arm 56 of switch 30 is deflected either upwardly or downwardly, as shown in the drawings, its contact will engage the contact on the arm 53 of 55 depending upon the direction in which the arm 56 is de flected to connect the said arms electrically.

As previously indicated, the switch 30 is operated by the selsyn receiver 22 and the mechanism for mounting and operating the switch includes a disk 59 mounted upon and rotated by the rotor or armature shaft 29 of the selsyn receiver 22. The peripheral edge of disk 59 is notched or slotted as at 60 to provide switch operating means in the form of a pair of spaced parallel surfaces 61 and 62 which extend at an angle between the opposite sides of the disk and form cam means for operating the switch 30 as explained in detail hereinafter.

Switch 30 is mounted through its arm 58 upon a carrier 63 in the form of a disk 64 having a central shaft 65 which extends through a bushing 66 in a panel 67 fixed with respect to the housing of the selsyn receiver 22 by brackets, not shown. Shaft 65 is provided with a shoulder 68 which abuts one end of the bushing 66 and it carries a control knob 69 which abuts the other end of bushing 66 to prevent axial movement of the shaft so that the spaced side by side relation of the disk 59 and 64 can not vary and so that the disk 64 can be rotated independently of the disk 59.

Rotation of the knob 66, and of course the disk 64 and switch 30, is limited to 360 degrees by means of a stop bar 70 pivotally mounted by a screw 71 to the panel 67. Stop bar 70 is swung from side to side between stop pins 72 by a pin 73 which extends downwardlyv from the bottoms of the knob 69 and engages the stop bar 70. In Figures 2 and 4 of the drawings the knob 69 has been rotated in a clockwise direction to themaximum extent and in this position the pin 73 on knob 69 engages one side of the stop bar 70 and the latter is in engagement with the upper stop pin 72. It will be seen that upon counterclockwise rotation of the knob 69 that pin 73 may be rotated only through 360 degrees because the pin 73 will come into engagement with the opposite side of stop bar 70 and swing it against the lower stop pin 72 as indicated in dotted lines in Figure 4.

The pin 73 in knob 69 is also urged downwardly against the panel 67 by spring means, not shown, which is contained within the knob 69 in order to provide a friction brake means between the panel 67 and the carrier 63 whereby the carrier 63 and switch 30 will not be rotated by the disk 64 as the latter is rotated by the selsyn receiver 22. i As clearly shown in Figure 2 of the drawings, the center contact arm 56 of switch 30 carries at its free end an operating means 74 including an insulating bar or rod 75 which depends from the arm 56 and carries a switch operating means in the form of a cam arm 76 that projects laterally therefrom and cooperates with the disk 59 and cam slot 60 therein to operate the switch 30. As previously mentioned, the switch 30 is a normally open reversing switch and it is so mounted by the carrier 63 that when it is in its open position its cam arm 76, which extends into the notch 60 and cooperates with the cam surfaces 61 thereof, is centered in the notch 60. It will be seen therefore, that relative rotation between the disk 59 and the carrier 63 will cause the cam surfaces 61 of notch 60 to cam the arm 76 either upwardly or downwardly, as shown in the drawings, to close the switch 30 and that upon sutficient relative rotation of these elements that the arm 76 will be caused to ride upon one side or the other of the disk 59. When switch 30 is open neither of the switches 37 or 41 is energized, but when the switch 30 is closed through contact arms 53 and 56 the switch 37 is energized and when the switch 30 is closed through contact arms 56 and 57 the switch 41 is energized.

In the operation of the apparatus above described, when it is desired to cause the antenna mast 23 to be rotated from one position to another, the knob 69 is rotated to a position in which it will correspond with the desired new position of the antenna 23. For this purpose, knob 69 and panel 67 may be provided with any suitable indicia, not shown. As shown in the drawings, the knob 69, carrier 63 and switch 30 have been rotated as a unit to a position corresponding to a position to which it is desired that the mast 23 shall rotate and stop. With reference to the drawings, it will be seen that the arm 76 has been cammed downwardly by one of the cam slots 61 and is engaging the underside of the disk 59 and that in this position the contacts on contact arms 56 and 57 are engaged to connect the arms 56 and 57 electrically.

When arms 56 and 57 are electrically interconnected and the electric circuit of the apparatus is energized, the switch 41 is operated to cause motor 20 to drive the antenna mast 23 and the armature 24 of selsyn transmitter 21 in one direction and, of course, the armature shaft 29 of selsyn receiver 22 will follow the rotation of the armature shaft 24 of the selsyn transmitter 21 until the disk 59, which is rotated thereby, rotates to such position that the arm 69 enters the cam slot 60 and moves to the center thereof to permit switch 30 to-open. Switch 30, upon opening, severs the electric circuit to switch 41 causing the latter to open to de-energize motor 20 and stop the rotation of mast 23 and the selsyn motors 21 and 22. 1 It will be seen that should the carrier 63 be rotated in the direction opposite to that described that the arm 76 "will be cammed upwardly by one of the cam surfaces 61 and onto the top side of disk 59 to close the contact arms 56 and 53 of switch 30 and that the closing of these contact arms energizes the-switch 37 to cause rotation of the motor 20, mast 23 and the armatures of the selsyn motors 21 and 22 in directions opposite to that first described above and that such rotation of these elements will be stopped when the arm 69 passes to the center of the cam slot 60.

It is pointed out that the switch 30 is so connected to the coils 50 and 51 of switches 37 and 41 respectively, and that the latter are so connected to motor 20 that when knob 69 is rotated in a clockwise direction that antenna 23 will also be rotated in a clockwise direction, and vice versa.

It is also pointed out that the selsyn motors 21 and 22 and transformer 47 are energized at all times when the apparatus is in operation in order that any slight drifting of the antenna 23 from its properly adjusted position will cause the selsyn receiver 22 to rotate disk 64 to operate switch 30 to reposition the antenna.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

I claim:

1. Apparatus for positioning a movable element from a position remote therefrom including a reversible electric motor for moving said movable element, an electric circuit through which current is supplied to said motor, a selsyn transmitter connected to be driven by said motor, a selsyn receiver electrically connected to be operated by said selsyn transmitter, switch means in said circuit for directing current to said motor to cause the latter to move said movable element in reverse directions and to stop, means rotated by said selsyn receiver for operating said switch means, and means for adjusting said switch to diflerent positions around said receiver operated switch operating means.

2. Apparatus for positioning a movable element from a position remote therefrom including a reversible electric motor for moving said movable element, an electric circuit through which current is supplied to said motor, a selsyn transmitter connected to be driven by said motor,

a selsyn receiver electrically connected to be operated by 4 said selsyn transmitter, switch means in said circuit for directing current to said motor to cause the latter to move said movable element in reverse directions and to stop, a disk rotated by said selsyn receiver, means on said disk for operating said switch to different positions, and means for rotating said switch to different positions around said disk.

3. Apparatus for positioning a movable element from a position remote therefrom including a reversible electric motor for moving said movable element, an electric circuit through which current is supplied to said motor, a selsyn transmitter connected to be driven by said motor, a selsyn receiver electrically connected to be operated by said selsyn transmitter, switch means in said circuit for directing current to said motor to cause the latter to move said movable element in reverse directions and to stop, a disk rotated by said selsyn receiver, cam means carried by said disk for operating said switch means, means cooperating with said cam means for operating said switch means, and means for rotating said switch means to different positions around said disk.

4. Apparatus for positioning a movable element from a position remote therefrom including a reversible electric motor for moving said movable element, an electric circuit through which current is supplied to said motor, a selsyn transmitter connected to be driven by said motor, a selsyn receiver electrically connected to be operated by said selsyn transmitter, switch means in said circuit for directing current to said motor to cause the latter to move said movable element in reverse directions and to stop, a disk rotated by said selsyn receiver, cam slot means in said disk, means for operating said switch means including means arranged to co'act with said cam slot means and the opposite side surfaces of said disk, and means for rotating said switch means to different positions around said disk.

References Cited in the file of this patent UNITED STATES PATENTS 

